The present disclosure generally relates to a method of controlling the radio communication of data messages between a plurality of field endpoints (in some cases utility meters) and a network of fixed location gateways which in turn communicate with a centrally located network controller. More specifically, the present disclosure relates to a method that optimizes the use of the communication channels by each of the plurality of endpoints to increase the overall effective message transmission capacity and where needed to increase the direct reach between a gateway and endpoint, thus enabling single-tier communications.
Presently, automated meter reading (AMR) systems exist that allow meters, such as electricity, gas and water meters, to communicate consumption information to a back end server through intermediate gateways. Typically, intermediate gateways communicate with the multiple meters using RF communication and re-transmit the received data over a public network, such as the internet. Although such systems, such as the FlexNet® AMI system available from Sensus USA, have proven effective at obtaining and processing meter data at a central, remote location, the increasingly common usage of such systems has increased the demand on the AMI or smart grid systems. As an example, in a system that includes 200 gateways and millions of individual meters, the communication taking place between the meters and the gateways has resulted in embodiments in which over 1 million messages are received by the gateways in aggregate per hour. Because of expanding applications, future smart grid systems are anticipated to exchange over 1 billion messages per day. Due to this increasingly high volume of communication between the meters and the gateways, techniques are required to more effectively utilize available bandwidth to enhance the communication between the various devices within the communication system. In addition, since real time control is required to protect the grid and to automatically respond to fault conditions, it is also important to minimize response time latency. This is also best accomplished by reducing the number of nodes where data must be handed off. Each hand-off requires that a node must receive a message, demodulate the message, apply error correction and possibly data decryption, repackage the message, set up the transmitter hardware and retransmit the messages, each step requiring processing time. Whereas mesh systems rely on multiple data hand offs between nodes, it is an object of this disclosure to minimize the number of handoffs thus improving latency. The minimal number of tiers is known to be one. Thus, an object of the disclosure is to provide reliable operation with a single communications tier.
Presently, when an individual meter is placed in a network system, the meter is assigned a communication channel over which communications between the meter and each of the gateways in the physical vicinity of the meter takes place. When an operator is setting up such a system, each meter is assigned a specific channel over which communication takes place. Although trained personnel attempt to select the communication channel based upon the proximity of the meter to a gateway or anticipated signal-to-noise ratio between the meter and a particular gateway, once the meter has been deployed, the communication channel frequency typically does not change unless the installer returns to reconfigure the meter or additional set-up is required at the network controller back-end. Therefore, although the operator may attempt to optimize the system upon deployment, if physical characteristics of the area change or if other variables are modified, the system will drop out of optimization, which is not desired.